Key for cylinder locks



A ril 9, 1935 E. N. JACQBI KEY FOR CYLINDER LOCKS Original Filed Nov. 3, 1953 m 1w :0 F 1W 0 E Patented Apr. 9 1935 Briggs & Stratton Corporatio I -;Wis.;'a'corporation of Delaware original application November 3; '19t3", seri aint. 1 696467. Divided and this application Qcfbbcr f :I

' :2 Claims.

for'c'ylindermm, and aid yision,or the co pending :application of Edward N. Jacobi, Serial No..696,4 6{7,filedNovember 3rd, 1933.

It is an object ofthis invention toiprovide a key of novel construction, particularly adapted forlcyl inder rlocksha ing transverse oppositely projected tumblers.

Another object ofthis invention is to provide a key of improved construction having both its edges bitted' for engagement with tumblers of a cylinder lock and means intermediate the tumbler engaging edges for engagement with a key; guiding rib extending down the keyway.

With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of partssubstantially as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

. The accompanying drawing illustrates two complete examples of the physical embodiment of the invention constructedaccording to the best mode so far devised for the practical application of the principles thereof, and in which: r

. Figure 1 is a perspective view of a key embodying this invention;

Figure 2 is a cross section view taken through Figure 1 on the plane of the line 2-2; v

Figure 3 is a perspective view'illustrating a modified embodiment of this invention; and

Figure 4 is a front elevation of a cylinderlock with the key of this invention in place, and shown in cross section.

Referring now more particularly to the accompanying drawing, in which like numerals ,indicate like parts, it is seen that the key consists of a blade 5 connected to a head by a shank l. The bladehas a groove 8 extending longitudinally along one side for engagement with a key guiding bar or rib 9 extending down the keyway of a cylinder look as shown in Figure '4, and more specifically brought out in the aforesaid copending application. The depth of this groove, as best shown in Figure 2, is greater than the major thickness of the blade and, in fact almost cuts the blade in two, so that the .bar or rib 9 in the' cylinder, by engaging the bottom 10 of the groove substantially divides the chambers. r g

As shown in Figure 4, in which the outer cap and dust cover are omitted for the sake 'of clarkeyway into two it a ek rway of the lockgc l n r is s a d that its .wau, at least iat'fthamouth of the keyway opposite the .keyguiding bar, closely surroundsfithefbarfand to; keep 1 the, opening at the mouth of the keywayas' s'mall as possib1e; ap-

proachesmlose t the facehof. the keywayjffrom shape of the blade above and beneath its longi-Y tudinal groove is taperingly increased asshown. In thismanner, the highest points on the. key, which do the most work and receive the greatest wear, inasmuch as the tumbler springs of the tumblers acted on by thehigh points are compressed the, maximum amount, have the widest 'i e w: i -i 7 a. KEY i on CYLInD'I-Jn-LOQ S l I M t t S, Edward N. Jacobi, Milwaukee, Wis'.,"a'ssignor to" p surfaces and lower tumbler engaging points, ion a 1 The wall ID of the groove forms in effect a I.

ridge extending longitudi'nally along the side of v the key blade opposite the groove and it is observed that the rear face of this wall lies in the plane of the adjacent face .of the handle or head 6. 1 1 r On the opposite face of the key, the surfaces of the blade are likewise flush with the adjacent face of the head 6, and as the major'thickness of the blade is less than the depth of the groove 8, it follows that the heador 'handleis of greater thickness than any portion of the blade. The shank I, besides'being thicker than the blade, also has greater width than the blade proper, to increase the strength of the key.

The possibility'of picking alock with which the key is used, is reduced to a minimum as the restriction of the space within the keyway is such that it is impossible to operatea picking tool. Further protection againstv possible picking may be afforded by extending a fin from thekey guiding rib completely across the keyway, and'to accommodate such fin, the-key may be formed as shown in Figure3, in which the bottom wall l2 V of, the groove 8 is longitudinally slotted as at I31 2 v f v 1,996,811

projected and in which the keyway is divided into which this invention appertains, that this invention provides a key of novel construction and one exceptionally well suited to cylinder locks in which transversely acting tumblers are actuated in opposite directions.

What, I claim as my invention is:

1. A key for tumbler locks in which the tumblers extend transversely and are oppositely projected, and in which the keyway is divided into twoparts by a-key guiding rib extending longitudinally downv the keyway, comprisinga blade having bittings along both edges and having a,

central groove extending longitudinally alongone face thereof to substantially divide the blade into two parts, and having its opposite face cut away at opposite sides of the groove to leave a thin walled connection between, the two part's'into which the blade is divided .by the groove and to give the ,two parts of the blade a substantially triangular cross section, the bases of the tritwo parts by a key guiding rib extending longitudinally down the keyway and the wall of the keyway opposite the key guiding rib lies closely around the key guiding rib' so as to leave but a thin space adjacent said rib to preclude the insertion of picking tools into the keyway, comprising, a blade having bittings along both edges and having a central groove extending longitudinally along one face thereof to substantially divide the blade into two parts and to slidably engage the key guiding rib of the lock, and having its opposite face cut away at opposite sides of the groove to leave but a thin wall connected between the two parts into which the blade is divided by the groove andv said cut away'portions being so shaped as' -to;give the two parts of the blade a substantially triangular cross section with the indleportion at one end of the blade.

EDWARD? n. JACOBI. 

